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Investigation of copper–azamacrocyclic complexes by high‐performance liquid chromatography
Author(s) -
Shen Xiaoxuan,
Boswell C. Andrew,
Wong Edward H.,
Weisman Gary R.,
Anderson Carolyn J.,
Tomellini Sterling A.
Publication year - 2006
Publication title -
biomedical chromatography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 65
eISSN - 1099-0801
pISSN - 0269-3879
DOI - 10.1002/bmc.525
Subject(s) - chemistry , copper , reagent , elution , high performance liquid chromatography , chromatography , organic chemistry
The use of copper radioisotopes in imaging and therapy has prompted an increased interest in chelators which form stable copper complexes, such as Cu(II)–azamacrocyclic complexes. The effects of charge, stability and the size of the macrocyclic backbone of the Cu(II)–azamacrocyclic complexes on biological behavior have been evaluated. Here we report a reversed‐phase high‐performance liquid chromatography (HPLC) method to separate several Cu(II)–azamacrocyclic complexes, including Cu(II) complexes of 1,4,8,11‐tetraazacyclotetradecane‐1,4,8,11‐tetraacetic acid (TETA), 4,11‐bis(carboxymethyl)‐1,4,8,11‐tetraazabicyclo[6.6.2]hexadecane (CB‐TE2A) and 4,10‐bis(carboxymethyl)‐1,4,7,10‐tetraazabicyclo[5.5.2]tetradecane (CB‐DO2A). Absorbance at 280 nm was used to monitor the complexes as they eluted from the reversed‐phase column. The effects of the concentration of the buffer, the pH of the buffered mobile phase and the concentration of the organic modifier, methanol, on the separation were investigated. Separation of these copper complexes by ion‐pair HPLC with the use of a mass spectrometry‐compatible ion‐pair reagent, triethylammonium acetate, in the mobile phase at pH 6.3 is also presented. The reversed‐phase chromatographic conditions utilized also allow the p K a s of Cu–TETA and the log( k ′ w ) values of Cu–CB‐TE2A, Cu–TETA and Cu‐CB‐DO2A to be estimated. Copyright © 2005 John Wiley & Sons, Ltd.